Merge pull request #693 from go-vgo/bitmap-pr

Update: update screen capture code and examples

.circleci/images/primary/Dockerfile

@@ -1,5 +1,5 @@
 # FROM golang:1.10.1
-FROM golang:1.22.3-stretch AS build
+FROM golang:1.23.2-stretch AS build
 # FROM govgo/go:1.11.1
 
 RUN apt update && apt install -y --no-install-recommends \

README.md

@@ -268,13 +268,18 @@ func main() {
   num := robotgo.DisplaysNum()
   for i := 0; i < num; i++ {
     robotgo.DisplayID = i
-    img1 := robotgo.CaptureImg()
+    img1, _ := robotgo.CaptureImg()
     path1 := "save_" + strconv.Itoa(i)
     robotgo.Save(img1, path1+".png")
     robotgo.SaveJpeg(img1, path1+".jpeg", 50)
 
-    img2 := robotgo.CaptureImg(10, 10, 20, 20)
+    img2, _ := robotgo.CaptureImg(10, 10, 20, 20)
     robotgo.Save(img2, "test_"+strconv.Itoa(i)+".png")
+
+    x, y, w, h := robotgo.GetDisplayBounds(i)
+		img3, err := robotgo.CaptureImg(x, y, w, h)
+		fmt.Println("Capture error: ", err)
+		robotgo.Save(img3, path1+"_1.png")
   }
 }
 ```
@@ -354,8 +359,8 @@ func opencv() {
   // bit1 := robotgo.CaptureScreen(10, 10, 30, 30)
   // img1 := robotgo.ToImage(bit1)
   // defer robotgo.FreeBitmapArr(bit0, bit1)
-  img := robotgo.CaptureImg()
-  img1 := robotgo.CaptureImg(10, 10, 30, 30)
+  img, _ := robotgo.CaptureImg()
+  img1, _ := robotgo.CaptureImg(10, 10, 30, 30)
 
   fmt.Print("gcv find image: ")
   fmt.Println(gcv.FindImg(img1, img))

examples/screen/main.go

@@ -29,23 +29,29 @@ func bitmap() {
 	gbitMap := robotgo.CaptureGo()
 	fmt.Println("Go CaptureScreen...", gbitMap.Width)
 	// fmt.Println("...", gbitmap.Width, gbitmap.BytesPerPixel)
-	// robotgo.SaveCapture("saveCapture.png", 10, 20, 100, 100)
+	robotgo.SaveCapture("saveCapture.png", 10, 20, 100, 100)
 
-	img := robotgo.CaptureImg()
+	img, err := robotgo.CaptureImg()
+	fmt.Println("error: ", err)
 	robotgo.Save(img, "save.png")
 
 	num := robotgo.DisplaysNum()
 	for i := 0; i < num; i++ {
 		robotgo.DisplayID = i
-		img1 := robotgo.CaptureImg()
+		img1, _ := robotgo.CaptureImg()
 		path1 := "save_" + strconv.Itoa(i)
 		robotgo.Save(img1, path1+".png")
 		robotgo.SaveJpeg(img1, path1+".jpeg", 50)
 
-		img2 := robotgo.CaptureImg(10, 10, 20, 20)
+		img2, _ := robotgo.CaptureImg(10, 10, 20, 20)
 		path2 := "test_" + strconv.Itoa(i)
 		robotgo.Save(img2, path2+".png")
 		robotgo.SaveJpeg(img2, path2+".jpeg", 50)
+
+		x, y, w, h := robotgo.GetDisplayBounds(i)
+		img3, err := robotgo.CaptureImg(x, y, w, h)
+		fmt.Println("Capture error: ", err)
+		robotgo.Save(img3, path2+"_1.png")
 	}
 }
 

robotgo.go

@@ -366,11 +366,11 @@ func CaptureGo(args ...int) Bitmap {
 	return ToBitmap(bit)
 }
 
-// CaptureImg capture the screen and return image.Image
+// CaptureImg capture the screen and return image.Image, error
 func CaptureImg(args ...int) (image.Image, error) {
 	bit := CaptureScreen(args...)
 	if bit == nil {
-		return nil, errors.New("capture error")
+		return nil, errors.New("Capture image not found.")
 	}
 	defer FreeBitmap(bit)
 

robotgo_test.go

@@ -179,7 +179,8 @@ func TestImage(t *testing.T) {
 	err := SavePng(img, "robot_test.png")
 	tt.Nil(t, err)
 
-	img1 := CaptureImg(10, 10, 20, 20)
+	img1, err := CaptureImg(10, 10, 20, 20)
+	tt.Nil(t, err)
 	e := Save(img1, "robot_img.jpeg", 50)
 	tt.Nil(t, e)
 

screen.go

@@ -11,7 +11,6 @@
 package robotgo
 
 import (
-	"errors"
 	"image"
 
 	"github.com/kbinani/screenshot"
@@ -31,7 +30,7 @@ func GetDisplayRect(i int) Rect {
 		Size{W: w, H: h}}
 }
 
-// Capture capture the screenshot
+// Capture capture the screenshot, use the CaptureImg default
 func Capture(args ...int) (*image.RGBA, error) {
 	displayId := 0
 	if DisplayID != -1 {
@@ -54,9 +53,9 @@ func Capture(args ...int) (*image.RGBA, error) {
 
 // SaveCapture capture screen and save the screenshot to image
 func SaveCapture(path string, args ...int) error {
-	img := CaptureImg(args...)
-	if img == nil {
-		return errors.New("Capture image not found")
+	img, err := CaptureImg(args...)
+	if err != nil {
+		return err
 	}
 
 	return Save(img, path)